I like this. I see it as adding a "select" feature (checkbox) on each individual asset that would allow user to select multiple pieces, and when 2 or more pieces are selected, it would enable a "bulk download" button that would exist somewhere in the Collection. The bulk download would automatically create a ZIP file with all the previously selected files. - I see this of high value, time saver and contributing to better CX.

In fact, in addition to the "bulk download", you could also have a "Add All Selected to Bundle"—now that would be awesome!

Multi-selecting pieces of content from within a Collection to download - or even be added to Bundles - is something we have talked about internally. At this point, we do not plan on making any major UI changes to Gallery Collections and in order to accommodate a change like this, we would do a redesign of this space.

We hope to tackle this in the future but again, have no immediate plans to make these changes.